Apparatus and method for mechanically opening a connection site

ABSTRACT

Method and apparatus are disclosed for mechanically opening a heat-bonded connection site between two hollow, flexible, thermoplastic segments of a medical fluid flow path, the heat-bonded connection site having an axis. The connection site is compressed between two facing surfaces, and the facing surfaces are relatively moved to rotate the connection site about the connection site axis and to apply force to the connection site substantially perpendicular to the connection site axis.

This application claims priority to and the benefit of U.S. ProvisionalPatent Application No. 62/516,214, filed Jun. 7, 2017, which is herebyincorporated by reference in its entirety.

BACKGROUND

The present disclosure generally relates to apparatus and methods foropening a connection site between two flexible thermoplastic conduits,such as, for example, a sterile connection site in fluid flow tubing ina medical fluid flow circuit employed in collecting, processing ortreating medical fluid such as blood or blood components.

It is well known in the medical industry in general and particularly inthe blood banking field to use connection systems for connecting twoseparate tubing segments of a fluid flow set or circuit in a manner thatprevents the introduction of contaminants or preserves the sterility ofthe tubing, if pre-sterilized, during the connection process. Suchsystems have found application both in the large scale assembly ormanufacture of fluid flow circuits and in the hands of the ultimate userfor on-site assembly of fluid flow circuits having a desiredconfiguration. For example, a user may desire to carry out a particularmedical procedure, such as for collecting, processing or treating bloodand blood components. These connection devices or systems are commonlyreferred to in the medical field as sterile connection or steriledocking devices.

Known connection devices or systems include electron beam systems, as inU.S. Pat. No. 5,009,645; radiant energy systems that melt facingmembranes of fluid flow conduits, as in U.S. Pat. No. 4,157,723, andheated wafer systems that employ expensive wafers for cutting andheating tubing segments that are bonded or spliced together while theends remain at a molten or semi-molten elevated temperature, such as inU.S. Pat. Nos. 4,753,697, 5,158,630, 5,156,701 and 5,279,685.

More recently, a novel rotary connection system and apparatus has beendescribed that connects flexible thermoplastic tubing segments by heator melt bonding the ends together while the ends are individuallyclamped into a closed position, preventing ambient contamination. Such asystem, which does not require the use of heated wafers, is described indetail in U.S. patent application publication no. 2013/0153048, which isincorporated by reference herein in its entirety.

The connection made by heated wafer systems as well as by the wafer-freeapparatus described above may have a temporary closed condition orcrimped shape due to the high temperature and clamping of the tubingsegment ends during connection. More specifically, as a result of theparticular connection process, a portion of thermoplastic material fromthe tubing, also referred to as a “skin”, “membrane” or “web,” may closeor reduce the size of the lumen between the tubing segments. In otherwords, after the connection is made, the tubular segments remain crimpedor stuck together at the connection site, and the cross section of thetubular segments is reduced or flattened along a seal line between thetubing segments. This thermoplastic blocking portion of the connectioncan be broken or otherwise disrupted to open the lumen for fluid flowbetween the tubing segments by light external pressure or manipulation,including manual or mechanical manipulation, at the connection point orsite. Examples of mechanical manipulation may be found in, for example,U.S. Pat. Nos. 4,610,670; 4,619,642 and 5,674,333 and EP No. 0599057 B1and WO 2011144561 A1. U.S. Pat. No. 9,533,135 shows the use of gaspressure or vacuum to open a connection site.

The subject matter of this description relates to an apparatus andmethod to automatically break or otherwise disrupt the thermoplasticskin or web and therefore more fully open such a connection site and thelumen of the tubing segments to allow or improve fluid flow between theconnected tubing segments.

BRIEF DESCRIPTION OF DRAWINGS

Turning now to a more detailed description of the present subjectmatter, which is presented for purposes of description and notlimitation, various aspects and features of the present subject are seenin the attached drawings, of which:

FIGS. 1A-1C show, for background purposes, an embodiment of the deviceand method for forming a heat-bonded connection described in theabove-cited U.S. published patent application publication no.2013/0153048, which is incorporated herein by reference.

FIG. 2 is an elevational view of a fluid processing system depicting howthe present subject matter maybe employed as part of a durable apparatusfor processing blood, blood components or other biological or othermedical fluids. The present connection opening apparatus and method alsocan be free-standing in a separate device or as part of other apparatus,such as connection apparatus that includes apparatus for forming aheat-bonded connection site.

FIGS. 3A and 3B are views, taken at different angles, of twothermoplastic tubes or tubing segments heat bonded or welded together byapparatus and method similar to that shown in FIGS. 1A-1C. Forconsistent reference purposes only, FIG. 3A is referred to as a top viewand is generally parallel to the connection site seal line formed by thecrimping action of the sealing or welding apparatus. The viewing angleof FIG. 3B is generally orthogonal to that of FIG. 3A. FIG. 3B isreferred to as a side view, and the viewing angle is generallyperpendicular to the connection site seal line formed by the crimpingaction of the connection sealing or welding apparatus.

FIGS. 4A and 4B are, respectively, diagrammatic line drawings of thetubing segments of FIGS. 3A and 3B, and are employed in later figures toillustrate the structure and function of apparatus and method describedherein for disrupting the web or skin blocking fluid flow through theconnection site after welding of the tubing or tubing segments togetherand opening the fluid flow lumen therethrough.

FIGS. 5A and 5B are, respectively, diagrammatic line drawings of thetubing or tubing segments of FIGS. 3A and 3B, showing the connectionsite located between a platform and a plate or roller in a first spacedapart position for receiving the tubing segment connection sitetherebetween.

FIGS. 6A and 6B are similar to the FIGS. 5A and 5B, but with theplatform and plate or roller shown in a second closer position forapplying pressure to the connection site located therebetween.

FIGS. 7A and 7B are similar to the FIGS. 6A and 6B, and also illustratea direction of relative motion as between the opposed platform and plateor roller for rotating or pivoting the connection site about thelongitudinal axis of the tubing or tubing segments, which passes throughthe connection site located therebetween.

FIGS. 8A and 8B illustrate a further embodiment and are, respectively,diagrammatic line drawings of the tubing segments of FIGS. 3A and 3B,showing the connection site located between opposed plates or rollers ina first spaced apart position for receiving the tubing segmentconnection site therebetween.

FIGS. 9A and 9B are similar to the FIGS. 8A and 8B, but with the opposedplates or rollers shown in a second closer position for applyingpressure to the connection site located therebetween.

FIGS. 10A and 10B are similar to the FIGS. 9A and 9B, and alsoillustrate a direction of relative motion as between the opposed platesor rollers for rotating the connection site about the longitudinal axisof the tubing or tubing segments, which passes through the connectionsite located therebetween.

FIGS. 11A-11E are cross sectional views of FIG. 4B, taken along line11-11 through the connection site, and diagrammatically illustrating thetubing or tubing segments and connection site rotated at differentangles between the compressive forces applied by opening apparatus asdescribed herein.

BRIEF SUMMARY OF DISCLOSURE

The following is a summary of various embodiments and/or aspects of thepresent subject matter and is not intended to include every embodimentor aspect or to provide a more detailed description, which may be foundin the later detailed description.

In accordance with the present subject matter, apparatus and method areprovided for opening or reducing blockage of a welded or heat-bondedconnection formed between two hollow, flexible, thermoplastic lengths oftubing or tubing segments, which connection includes a portion ofthermoplastic material at least partially blocking internalcommunication between the conduits. As used herein “reducing theblocking,” does not require that the entire blockage be completelyremoved, but that the amount of blockage is reduced so that flow orenhanced flow (which may differ significantly in different applications)is provided through the connection site between the tubing segments.“Tubing,” tubing extension” and “tubing segment” are usedinterchangeably.

The present subject matter may be used in a stand alone device foropening tubing connection sites or may be employed in combination withapparatus that forms the welded or heat bonded connection between thetwo tubing segments, such as that described in U.S. publishedapplication, publication no. 2013/0153048, or other connection devices.The present subject matter may also be part of or employed in a largerblood processing apparatus that includes, for example, pumps, valves,optional blood separation devices and the like for processing blood orblood components or other medical fluids through a disposable medicalfluid flow system, either simultaneously as the blood or bloodcomponents are collected from a donor or patient or duringpost-collection processing (without connection to a donor or patient) ofpreviously collected blood or blood components. Such processingapparatus may also optionally include apparatus for forming a heatbonded connection site between thermoplastic tubing segments of such amedical fluid flow system. As used herein, “blood” is intended toinclude whole blood and blood components such as plasma or concentratedred cells, either with or without other blood components or addedliquids such as anticoagulant, and “medical fluids” is intended to havea comprehensive definition to include all of the above and any otherbiological, medicinal, therapeutic, diagnostic or medical treatmentfluid or fluid employed in a medical processor.

In accordance with a first aspect of the present subject matter, theconnection opening system may be provided as part of a larger connectionsystem or apparatus that includes, without limitation, apparatus forforming a welded connection between thermoplastic tubing segments. Inthis aspect, the larger connection apparatus or system may comprise (1)a connection forming station employing apparatus for forming aheat-bonded connection site between two hollow, flexible, thermoplasticsegments of a medical fluid flow path, the joined tubing segments havinga longitudinal axis extending through the heat-bonded connection site(referred to as the connection site axis), and (2) a connection siteopening station for opening the heat-bonded connection site. Theconnection site opening station, as described herein, may include twofacing surfaces that can be spaced apart sufficiently to receive the twosegments and the heat bonded connection site between the facingsurfaces, the facing surfaces being relatively movable to rotate theconnection about the connection site axis and preferably simultaneouslyapply force to the connection site substantially perpendicular to theconnection site axis.

In accordance with another aspect, the connection opening system may beprovided as a separate or free-standing device for opening a heat-bondedconnection site between two hollow, flexible, thermoplastic tubingsegments of a medical fluid path. The connection opening system of thisaspect may include a connection site opening station comprising at leasttwo facing surfaces; the facing surfaces being relatively movable to aspaced apart position where they are spaced sufficiently to receive theheat bonded connection site between the facing surfaces; and the facingsurfaces being relatively movable to rotate the connection about theconnection site axis and, preferably simultaneously, apply force to theconnection site substantially perpendicular to the connection site axis.

In accordance with a further aspect, the connection opening system maybe provided as part of a durable blood processing apparatus operable toprocess blood or blood components through a disposable medical fluidflow system. Such a durable blood processing apparatus may include oneor more pumps or valves for controlling flow of blood or bloodcomponents through the disposable medical fluid flow system and aconnection site opening station for opening a heat-bonded connectionsite formed between thermoplastic tubing segments of the medical fluidflow system. The connection site opening station may include at leasttwo facing surfaces that can be spaced apart sufficiently to receive thetwo segments and the heat bonded connection site between the facingsurfaces, the facing surfaces being relatively movable to rotate theconnection about the connection site axis and, preferablysimultaneously, apply force to the connection site substantiallyperpendicular to the connection site axis. Such a durable processingdevice may also include apparatus for making or forming the heat bondedconnection between tubing segments.

In accordance with yet another aspect, a method of opening a heat-bondedconnection may be provided employing any of the systems or apparatus ofthe above aspects or in the additional aspects set forth below.

Further aspects of the present subject matter or that may be employedwith the present subject matter are set forth below.

DETAILED DESCRIPTION

Turning now to a more detailed description, the attached drawings areprovided for purposes of illustration and not limitation. As notedearlier, the present subject matter is particularly useful in opening aheat or melt bonded or welded connection site formed by connectiondevices such as, but not limited to that illustrated in U.S. publishedpatent application publication no. 2013/0153048. FIGS. 1A-1C are takenfrom that application and illustrate, for background and descriptionpurposes, one example of a prior device and method for forming aheat-bonded (also referred to interchangeably as “melt-bonded” or“welded”) connection between two flexible thermoplastic conduits ortubes.

Illustration of this particular device does not imply that the presentsubject matter is useful only with heat or melt bonded connectionsformed by such device. Connections formed by other apparatus may also beused with the present subject matter. Without unduly elaborating on thedetails of the device and method shown in the above application, whichare fully explained in the published application, sealed thermoplasticconduit tubing or tubing segments 20 and 22 are each received on arotatable disc, respectively 24 and 26. Each disc cooperates with twopair of clamping jaws 28 and 30, one of which may also be a highfrequency voltage electrode for heating the clamped tubing. As seen inFIG. 1B, after the tubing segments are clamped and heated, the discsshift laterally to separate the clamping jaws and rotate to thepositions seen in FIG. 1B. This exerts a tensile and shear force on thetubing segments, such that each tubing segment is separated from thesealed end portion of that segment. Because the clamping jaws 28 keepthe ends of the segments clamped and sealed, sterility of the segments,if pre-sterilized, is maintained and, in any event, the tubing segmentsare safeguarded from introduction of ambient bacteria or microorganisms.

After the tubing segment ends are brought into a facing position byrotation of the discs, as shown in FIG. 1B, the discs move laterallyagain, bringing the tubing segment ends into direct contact. Becausethis happens while the tubing ends are still at elevated temperature andin semi-molten state, they form an integral, welded bond or heat-bondedconnection site (better seen as connection site 84 in FIGS. 3A, 3B, 4Aand 4B). Because the process may result in a thermoplastic portion or“skin” blocking communication between the lumen of the joined conduitsor tubes (see FIGS. 3A, 3B, 4A and 4B), after cooling, manualmanipulation may be employed to break the skin and open the connectionbetween the tubing segments for fluid flow. The present subject matter,as described below, avoids the need for manual manipulation.

FIG. 2 shows one embodiment that serves to illustrate the use of thepresent connection site opening apparatus and methods summarized above,as part of a larger fluid processing system. The system shown is forpurposes of illustration and not limitation to the features of theparticular system shown. More specifically, FIG. 2 depicts a medicalfluid processing system, generally at 50, for processing medical fluidsuch as blood, including blood collected from a donor. The systemincludes a reusable, durable processing device 52, upon which adisposable, one-time use fluid flow circuit 54 may be mounted. Theillustrated durable device includes, as necessary, valves or pumps forcooperating with the fluid flow circuit to control the flow of blood,blood components and other liquids through the circuit and carry out thedesired processing. Depending on intended use, the durable device mayoptionally also include sensors, hangers, scales, drive systems,separation devices and the like.

The disposable fluid flow circuit 54 is, at least in part, preassembledand pre-sterilized, and may be made up of fluid flow tubing, and anydesired containers and processing devices that may be assembled onto thedurable device for conveying blood, blood components and/or otherassociated fluids through the fluid processing circuit withoutintroducing extraneous materials or contaminants. Only the disposable,one-time use fluid flow circuit contacts the blood or other liquids,thus avoiding the need to sterilize the durable hardware components andsignificantly reducing administrative burdens and costs associated withthe processing.

As illustrated, the durable portion of the system may include, amongother things, one or more flow control valves 56 a-c for assisting incontrolling flow through flexible plastic tubing 58 of the fluid flowcircuit 54. Typically, each valve includes a pair of clamping orpinching jaws, between which fluid flow tubing of the fluid flow circuitis placed when the flow circuit is assembled onto the face of the device52. The valves close or open the tubing in response to commands from theoperating control system of the device 52 based on the particularprocess selected by the user. Typically, but not exclusively, thecontrol system for device 52 employs a programmable microprocessor basedcontroller that allows the device to be configured for one or more ofdifferent selected procedures for processing blood, blood components orother biological or medical fluids. In the present description, thesystem is shown, for illustrative purposes only, for processing aunit/container of previously whole blood collected from a donor, forexample in a prior collection procedure. The whole blood may beprocessed, for example, to separate it into concentrated red cells,plasma and platelets, each of which finds application in particularmedical situations, thus resulting in more efficient usage of thecollected blood. The present subject matter may also be used inconnection with a disposable fluid flow circuit and durable device thatprocesses blood collected while the donor or patient is attached to thedevice.

The durable device 52 may also include optionally one or more pumps 60a-c, such as peristaltic type pump, operable on the tubing 58 of thefluid flow circuit to direct flow therethrough. In addition, the durabledevice may also optionally include a station 62 for receiving andinteracting with a blood separation device, and various other sensors,weigh scales and other components to control fluid processing throughthe fluid flow circuit. For example, the disposable fluid flow circuit54 illustrated in FIG. 2 may include, for example, a blood separationdevice 74, one or more containers or bags 76 (e.g., containing RBCadditive solution), 78 (e.g., for receiving concentrated RBCs) and 80(e.g., for receiving plasma), leukoreduction filter 82 and associatedflexible tubing 58 connecting the various components in a fluid flowrelationship. The preassembled circuit may be pre-sterilized, and thetubing extensions or tubing segments 66 and 68 may, before joinder,terminate at a heat sealed end to preserve sterility.

When mounted on the illustrated durable device, the components of thepreassembled flow circuit are placed on or in their selected locations,for example, the blood separation device 74 in the station 62, thetubing in the valves 56, sensors, and pumps 60 and the bags 76-80 on thevarious hangers. To carry out the illustrated blood processing, a bag ofpre-collected blood 70 is suspended from the appropriate hook or hangerand tubing segments 66 and 68 of the fluid circuit, are placed inoperative position on a connection forming apparatus, generally at 64,as illustrated in more detail in FIGS. 1A-1C—which may include apparatussuch as but not limited to that described in U.S. published applicationpublication no. 2013/0153048, for forming a heat-bonded connection, suchas a sterile connection, between tubing segments that are joined to formpart of the disposable fluid flow circuit.

Before turning to further details of the present opening method andapparatus, it should be noted that it is not required, either for theconnection forming apparatus 64 of the above published application orfor the subject matter described herein, that the conduits to be ofexactly the same size or material, although the material and size shouldbe sufficiently compatible as necessary to form the heat-bondedconnection. It is contemplated for application in medical fluid flowcircuits that the tubing or tubing segments will typically be flexibletubing of polyvinyl chloride (“PVC”) or other flexible thermoplasticmaterial, with an interior lumen for flowing medical fluids such asblood, blood components, anticoagulant, saline, or other liquids. In atypical fluid flow circuit for collecting, processing or treating bloodor blood components, such as the type marketed by Fenwal Inc., of LakeZurich, Ill., the fluid flow tubing may be hollow PVC tubing, a flexiblethermoplastic material, having an internal lumen diameter of about0.118-0.126 inches (3-3.2 mm) and a wall thickness of about 0.025-0.03inches (0.635-0.762 mm). As noted above, however, this subject matter isnot limited to a particular size or material for the conduits.

In the illustrated embodiment, the connection formed is between aflexible thermoplastic (PVC) tubing segment 66 of the preassembleddisposable fluid circuit 54 and flexible thermoplastic (PVC) flow tubingsegment 68 attached to a container or bag 70 of collected blood,although it is not necessarily attached to a bag or container.

As explained earlier, when the connection between the tubing segments isformed by the connection apparatus 64, a thermoplastic portion or skinmay be formed during the connection process and blocks or reduces flowthrough the tubing segments 66 and 68. In that condition, the tubingsegments may appear substantially as show in FIGS. 3A and 3B, with thetubing wall compressed together and held by a plastic web or skin at theconnection site 84, as best seen in “top view” of FIG. 3A, and the heatbonded connection being in the form of or extending in a line 85, whichis oblique or transverse to the longitudinal axis (i.e., the connectionsite axis 88) of the tubing, as best seen in the “side view” of FIG. 3B.

As explained earlier, the present subject matter is directed toapparatus and method for disrupting the connecting web or skin ofthermoplastic material and automatically opening the heat bondedconnection site 84 as shown, for example, in FIGS. 3A and 3B. Althoughdescribed in part with respect to a blood processing device 52, to beabundantly clear, the opening apparatus and method described herein maybe employed in any suitable arrangement, and this description is by wayof example only and not limitation. For example, the opening apparatusand method described herein may be configured as an entirely separatedevice for the sole purpose of opening heat bonded connection sites; orit may be employed in combination with apparatus for forming the heatbonded connections as part of a device that is devoted to forming andopening heat bonded connections and is separate from any larger bloodprocessing system; or it may be employed alone or in combination withconnection forming apparatus on a larger fluid processing device forprocessing blood, blood components, other biological or medical fluids;or it may be employed in any other desired application or arrangement.

For purposes of illustration only, in FIG. 2 the connection site openingapparatus is shown diagrammatically on the face of the durable device,and generally referred to as opener 86. The opener 86 may be located ata convenient site on the processing device 52 to allow the tubingsegments and connection site to be manually or automatically moved fromthe connecting apparatus 64 to the opener 86.

The tubing or tubing segments 66 and 68, the connection site 84 and theopener 86 and method for opening the connection site are shown morefully in FIGS. 3A-10B. For purposes of describing the connection siteopening method and apparatus herein, reference may be made to thelongitudinal axis 88, shown in FIGS. 3A and 3B, that extends axiallythrough the lumen or bore of tubing segments 66 and 68 and passesthrough the seal line 85 at the connection site 84. This axis will bereferred to at the connection site axis.

When the heat bonded or welded connection site is formed, associatedclamps typically compress or clamp the tubing segments in proximity toconnection site, resulting in a physical appearance of the connectedtubing segments 66 and 68 as seen in FIGS. 3A and 3B, wherein theconnection site, before opening, extends along a line 85 that may betransverse or orthogonal to the connection site axis 88. FIG. 3A showsthe compressed tubing segments 66 and 68 when looking at an end edge ofthe connection site line. FIG. 3B is from a viewing angle 90 degreesfrom the viewing angle of FIG. 3A, and shows the connection site line 85along its length, and the outward flaring of the tubing segments at theconnection site as a result of the jaws that clamp the tubing during theformation of the connection site. Because of the connection formingprocess the compressed walls of the tubing segments tend to sticktogether along the connection or bonding site line 85, thus blocking orreducing flow between the tubing segments.

FIGS. 4A and 4B show the tubing segments 66 and 68 and connection site84 of FIGS. 3A and 3B diagrammatically as line drawings, and will beemployed in the discussion below to better illustrate the openingapparatus and method. Further, for consistent reference purposes, FIG.3A and similar line drawings viewing the connection site seal line 85from an end or edge view are labeled 3A, 4A, 5A etc. and are referred toas the top view, and FIG. 3B and similar line drawings showing thelength of the connection site seal line 85 are labeled 3B, 4B, 5B etc.and are referred to as the side view. It is thus apparent that the topand side views are taken orthogonally, at 90 degrees, relative to oneanother.

The opening method and apparatus as described below employs at least twofacing surfaces of any suitable shape or configuration, between whichthe connection site 84 can be positioned. The surfaces are relativelymovable by any suitable means (not shown), such as a motor or solenoidor other mechanical, electrical, pneumatic or hydraulic drive, to rotatethe connection site about the connection site axis 88 and to apply forceto the connection site that is substantially perpendicular to theconnection site axis 88, compressing the connection site as it isrotated or pivoted. Preferably, but not necessarily, the compressiveforce is applied simultaneously with the rotation. The connected tubingsegments 66 and 68 may be rotated about the connection site axis 88without moving in another direction or may also translate in anotherdirection, such as laterally or at a right angle to the connection siteaxis, while being rotated. The rotation results in the surfacesperiodically applying a compressive force against the end edges of theconnection site seal line 85 (e.g., twice during each 360 degrees ofrotation as illustrated in FIGS. 11A and 11E), which tends to help openthe connection site and to reshape the connection site into a roundedinstead of a flattened condition to allow fluid flow between the tubingsegments. The relative movement of the surfaces may be in the samedirection or in opposite directions or may also be reciprocating, sothat the connection site is rotated in one direction and then in areverse direction, in a “back and forth” manner to repeatedly applycompressive force to the ends of the connection site seal line. Theamount of rotation induced by relative movement of the surfaces may befixed or variable. For example, the connection site may be rotated aboutthe connection site axis a fixed amount of about 180-720 degrees, suchas 180-360 degrees in one direction or, if the relative movement isreciprocating, the amount of rotation could be the same or variable inopposite directions. As a further example, the connection site could berotated a first amount in one direction and then a greater or lesseramount in the opposite direction. Similarly, the amount ofpressure/force applied by the surfaces may vary, such as increasing ordecreasing or alternately increasing and decreasing. This may becontinued until the connection site is opened, which may be confirmedvisually, tactilely or automatically such as by sensing internalpressure variation within the tubing segments.

Turning now to FIGS. 5A and 5B, illustrated there is an arrangement inwhich one of the surfaces is the surface of a plate or roller 90 and theother surface is the facing surface of a facing platform 92. FIGS. 5Aand 5B show the respective surfaces spaced apart sufficiently to allowat least the connection site 84 to be positioned between them. In thisarrangement, the platform is relatively stationary and the roller orplate has two degrees of freedom, being movable toward and away from theplatform surface as reflected by the arrow in FIG. 5B so as to exert aforce against the end edges of the connection site 84, and movable fromside to side or laterally relative to the platform surface as indicatedby the arrow in FIG. 5A, so as to cause rotation of the tubing segments.Alternatively, the platform 92 could be movable and the plate or roller90 stationary, or they could both be movable.

FIGS. 6A and 6B show the roller or plate 90 moved to a closer positionrelative to the platform 92, applying a compressive force againstconnection site 84 and specifically against the end edges of theconnection site seal line 85, squeezing the ends toward one another. Inother words, the compressive force is generally perpendicular to theconnection site axis 88 and parallel to the connection site seal line 85as seen in 6B. The roller or plate 90 would then be moved laterally,parallel to the surface of platform 92, as described below.

FIGS. 7A and 7B show the system of FIGS. 5 and 6, illustrating lateralmovement, such as reciprocating movement, of the plate or roller 90relative to the platform 92 as indicated by the arrow in FIG. 7A. Themovement may be described as parallel to the plane of the page in FIG.7A and into or out of the page in FIG. 7B. The lateral movement of theplate or roller while contacting and compressing the connection site 84causes the connection site and tubing segments to rotate or pivot aboutthe connection site axis, applying force to the connection site fromvarious directions, as illustrated in FIG. 11A-11E. This causesdeformation of the connection site from the flattened connectionimmediately after the connection is formed (see FIGS. 3A and 3B) to amore rounded condition, disrupting the blocking web or skin of the sealor weld between the opposed walls of the tubing segments, while leavingintact the connection between two tubing segments 66 and 68, and openingthe connection site to fluid flow between the tubing segments. While theopposed surfaces are illustrated here as the surface of the platform 92and the surface of the roller or plate 90, it should be understood thatother suitable shapes or configurations could be used that can achievecompression and rotation of the connection site.

FIGS. 8A and 8B show an alternative embodiment, similar to FIG. 5, butillustrating the connection site 84 between opposed surfaces in the formof facing plates and/or rollers 94 and 96, each of which has twoorthogonal degrees of freedom of movement. Both opposed surfaces couldbe in the form of plates or rollers or one could be a plate and one aroller or other shapes could be used to achieve that are suitable toexert the needed force on the connection site and to impart rotation ofthe connection site. As shown in FIG. 8B, as depicted by the arrows,each plate or roller is relatively movable toward and away from theother (parallel to the surface of the page) to compress the connectionsite in an end to end direction, although only one could be movable. Asindicated by the arrow in FIG. 8A, both of the plates or rollers alsoare also laterally movable relative to one another to apply compressiveforce to the connection site, although this also could be varied. FIGS.8A and 8B show the facing plates or rollers in a spaced apart positionto allow positioning of the connection site therebetween.

FIGS. 9A and 9B show the rollers or plates 94 and 96 after they moved toa closer position, applying a compressive force against connection site84 and particularly against the end edges of the connection site sealline 85 such that the direction of the force is substantially parallelto the seal line of the connection site. In other words, similar to FIG.6, the compressive force exerted on the connection site is generallyparallel to the connection site seal line 85 and perpendicular to theconnection site axis 88.

FIGS. 10A and 10B show the system of FIGS. 8 and 9, illustrating lateralmovement of the plates or rollers 94 and 96 relative to each other afterapplication of force against the connection site as shown in FIGS. 9Aand 9B, as indicated by the arrow in FIG. 10A. In this example, theplates or rollers are movable simultaneously in opposite lateraldirections, such that with reference to FIG. 10B plate or roller 94 isillustrated moving in direction into or out of the plane of the paperand plate or roller 96 is also illustrated as moving into or out of theplane of the paper. With reference to FIG. 10A, the movement is parallelto the plane of the page. The relative lateral movement of the plates orrollers while contacting and compressing the connection site 84, asshown in FIG. 10A, causes the connection site and tubing segments torotate or pivot about the connection site axis, thus applying force tothe connection site from various directions, as illustrated in FIG.11A-11E, as the connection site rotates or pivots. This causesdeformation of the connection site from the flattened connectionimmediately after the connection is formed (see FIGS. 3A and 3B) to amore rounded condition, disrupting the blocking web or skin of the sealor weld between the opposed walls of the tubing segments, while leavingintact the connection between two tubing segments 66 and 68, and openingthe connection site to fluid flow between the tubing segments. While theopposed surfaces are illustrated here as the surface of a plate and thesurface of a roller or plate, it should be understood as noted earlierthat other combinations of rollers and/or plates and other suitableshapes or configurations and different directions of movement could beused that can achieve compression and rotation of the connection site.

Various Additional Aspects

In accordance with a first aspect of the present subject matter,referred to as aspect no. 1, as noted earlier, the connection openingsystem may be provided as part of a larger connection system orapparatus that includes, without limitation, apparatus for forming awelded connection between thermoplastic tubing segments. In this aspect,the larger connection apparatus or system may comprise (1) a connectionforming station employing apparatus for forming a heat-bonded connectionsite between two hollow, flexible, thermoplastic segments of a medicalfluid flow path, the joined tubing segments having a longitudinal axisextending through the heat-bonded connection site (referred to as theconnection site axis), and (2) a connection site opening station foropening the heat-bonded connection site. The connection site openingstation, as described herein, may include two facing surfaces that canbe spaced apart sufficiently to receive the two segments and the heatbonded connection site between the facing surfaces, the facing surfacesbeing relatively movable to rotate the connection about the connectionsite axis and preferably simultaneously apply force to the connectionsite substantially perpendicular to the connection site axis.

In accordance with aspect 2, the connection system of aspect 1 mayinclude one of the facing surfaces being substantially stationary andthe other of the facing surfaces being movable with at least two degreesof freedom.

In accordance with aspect 3, the connection system of aspect 1 mayinclude each of the facing surfaces being movable with at least onedegree of freedom.

In accordance with aspect 4, the connection system of any one of aspects1-3 may include at least one of the facing surfaces being substantiallycylindrical.

In accordance with aspect 5, the connection system of any one of aspects1-4 may include at least one of the facing surfaces being generally orsubstantially planar.

In accordance with aspect 6, the connection system of any one of aspects1-5 may include at least one of the facing surfaces being movable withat least one degree of freedom in one direction and the other facingsurface being movable with at least one degree of freedom in a differentdirection.

In accordance with aspect 7, the connection system of aspect 6 mayinclude the other facing surface being movable in a different directionthat is substantially orthogonal to the one direction.

In accordance with aspect 8, the connection system of any of aspects 1-7may include one of the facing surfaces being substantially cylindricaland rotatable about its own axis of rotation and the other facingsurface being substantially planar and movable in a directionsubstantially perpendicular to the axis of rotation of the cylindricalsurface.

In accordance with aspect 9, the connection system of any one of aspects1-3 and 5-7 may include each of the facing surfaces being substantiallyplanar and one of the facing surfaces being movable in a directiongenerally perpendicular to the surface of the other of the facingsurfaces, and the second facing surfaces being movable in a directionsubstantially parallel to the first facing surface.

In accordance with aspect 10, as noted earlier, the connection openingsystem may be provided as a separate or free-standing device for openinga heat-bonded connection site between two hollow, flexible,thermoplastic tubing segments of a medical fluid path. The connectionopening system of this aspect may include a connection site openingstation comprising at least two facing surfaces; the facing surfacesbeing relatively movable to a spaced apart position where they arespaced sufficiently to receive the heat bonded connection site betweenthe facing surfaces; and the facing surfaces being relatively movable torotate the connection about the connection site axis and, preferablysimultaneously, apply force to the connection site substantiallyperpendicular to the connection site axis.

In accordance with aspect 11, the connection opening system of aspect 10may include one of the facing surfaces being substantially stationaryand the other of the facing surfaces being movable with at least twodegrees of freedom.

In accordance with aspect 12, the connection opening system of aspect 10may include each of the facing surfaces being movable with at least onedegree of freedom.

In accordance with aspect 13, the connection opening system of any oneof aspects 10-12 may include at least one of the facing surfaces beingsubstantially cylindrical.

In accordance with aspect 14, the connection opening system of any oneof aspects 10-13 may include at least one of the facing surfaces beinggenerally planar.

In accordance with aspect 15, the connection opening system of any oneof aspects 10-14 may include at least one of the facing surfaces beingmovable with at least one degree of freedom in one direction and theother facing surface being movable with at least one degree of freedomin a different direction.

In accordance with aspect 16, the connection opening system of aspect 15may include the other facing surface being movable in a differentdirection that is substantially orthogonal to the one direction.

In accordance with aspect 17, the connection opening system of any ofaspects 10-16 may include one of the facing surfaces being substantiallycylindrical and rotatable about its own axis of rotation and the otherfacing surface being substantially planar and movable in a directionsubstantially perpendicular to the axis of rotation of the substantiallycylindrical surface.

In accordance with aspect 18, the connection opening system of any oneof aspects 10-12 and 13-16 may include each of the facing surfaces beingsubstantially planar and one of the facing surfaces being movable in adirection generally perpendicular to the surface of the other of thefacing surfaces, and the second facing surfaces being movable in adirection substantially parallel to the first facing surface.

In accordance with aspect 19, as noted earlier, the connection openingsystem may be provided as part of a durable blood processing apparatusoperable to process blood or blood components through a disposablemedical fluid flow system. Such a durable blood processing apparatus mayinclude one or more pumps or valves for controlling flow of blood orblood components through the disposable medical fluid flow system and aconnection site opening station for opening a heat-bonded connectionsite formed between thermoplastic tubing segments of the medical fluidflow system. The connection site opening station may include at leasttwo facing surfaces that can be spaced apart sufficiently to receive thetwo segments and the heat bonded connection site between the facingsurfaces, the facing surfaces being relatively movable to rotate theconnection about the connection site axis and, preferablysimultaneously, apply force to the connection site substantiallyperpendicular to the connection site axis.

In accordance with aspect 20, the durable blood processing apparatus ofaspect 19 may include one of the facing surfaces being substantiallystationary and the other of the facing surfaces being movable with atleast two degrees of freedom.

In accordance with aspect 21, the durable blood processing apparatus ofaspect 20 may include each of the facing surfaces being movable with atleast one degree of freedom.

In accordance with aspect 22, the durable blood processing apparatus ofany one of aspects 19-21 may include at least one of the facing surfacesbeing generally cylindrical.

In accordance with aspect 23, the durable blood processing apparatus ofany one of aspects 19-22 may include at least one of the facing surfacesbeing generally planar.

In accordance with aspect 24, the durable blood processing apparatus ofany one of aspects 19-23 may include at least one of the facing surfacesbeing movable with at least one degree of freedom in one direction andthe other facing surface being movable with at least one degree offreedom in a different direction.

In accordance with aspect 25, the durable blood processing apparatus ofaspect 25 may include the other facing surface being movable in adifferent direction that is substantially orthogonal to the onedirection.

In accordance with aspect 26, the durable blood processing apparatus ofany of aspects 19-25 may include one of the facing surfaces beingsubstantially cylindrical and rotatable about its own axis of rotationand the other facing surface being substantially planar and movable in adirection substantially perpendicular to the axis of rotation of thesubstantially cylindrical surface.

In accordance with aspect 27, the durable blood processing apparatus ofany one of aspects 19-21 and 23-27 and may include each of the facingsurfaces being substantially planar and one of the facing surfaces beingmovable in a direction generally perpendicular to the surface of theother of the facing surfaces, and the other facing surface being movablein a direction substantially parallel to the one facing surface.

In accordance with aspect 28, a method of opening a heat-bondedconnection may be provided employing any of the systems or apparatus ofaspects 1-27.

In conclusion, although the present subject matter has been describedwith reference to specific devices and methods, this is for the purposeof description and not limitation. It is contemplated, for example, thatthis subject matter may be used with other devices, systems and methods,and reference should be made to the attached claims for an understandingof the scope of certain aspects of the present subject matter.

The invention claimed is:
 1. A method of opening a heat-bondedconnection site between two hollow, flexible, thermoplastic segments ofa medical fluid path defined by a seal line having a connection siteaxis, with a connection site opening station comprising a roller havinga first substantially cylindrical surface rotatable about a first axisand a plate having a second substantially planar surface facing thefirst cylindrical surface, one of the roller and the plate beingmoveable perpendicular to the first axis of the roller between a firstposition in which the facing surfaces are spaced apart sufficiently toreceive the two segments and the connection site between the facingsurfaces and a second position in which the facing surfaces apply aforce to the connection site substantially in alignment with theconnection site axis, the roller being movable laterally back and forthrelative to the plate when in the second position, the methodcomprising: a) placing the connection site between the facing surfacesof the connection site opening station; b) moving the surfaces tocompress the connection site substantially perpendicular to theconnection site axis; and c) rotating the connection site substantiallyabout the connection site axis.
 2. The method of claim 1 in which thecompressing and rotating occur simultaneously.
 3. The method of claim 1in which the connection site is rotated in a first direction and then ina second direction.
 4. The method of claim 3 in which the connectionssite is rotated a first amount in the first direction and a secondamount in the second direction.
 5. The method of claim 4 in which thefirst amount and second amount are fixed.
 6. The method of claim 4 inwhich the first amount and second amount are variable.
 7. The method ofclaim 4 in which the first amount is different from the second amount.8. The method of claim 4 in which the first amount is equal to thesecond amount.
 9. The method of claim 4 in which the first amount isless than the second amount.
 10. The method of claim 4 in which thefirst amount is greater than the second amount.
 11. A method of formingand opening a heat-bonded connection site between two hollow, flexible,thermoplastic segments of a medical fluid path defined by a seal linehaving a connection site axis, with a connection system comprising aconnection forming apparatus and a connection site opening station, theconnection site opening station further comprising a roller having afirst substantially cylindrical surface rotatable about a first axis anda plate having a second substantially planar surface facing the firstcylindrical surface, one of the roller and the plate being moveableperpendicular to the first axis of the roller between a first positionin which the facing surfaces are spaced apart sufficiently to receivethe two segments and the connection site between the facing surfaces anda second position in which the facing surfaces apply a force to theconnection site substantially in alignment with the connection siteaxis, the roller being movable laterally back and forth relative to theplate when in the second position, the method comprising: a) forming theconnection site with the connection forming apparatus; b) placing theconnection site between the facing surfaces of the connection siteopening station; c) moving the surfaces of the connection site openingstation to compress the connection site substantially perpendicular tothe connection site axis; and d) rotating the connection sitesubstantially about the connection site axis.
 12. The method of claim 11in which the compressing and rotating occur simultaneously.
 13. Themethod of claim 11 in which the connection site is rotated in a firstdirection and then in a second direction.
 14. The method of claim 13 inwhich the connections site is rotated a first amount in the firstdirection and a second amount in the second direction.
 15. The method ofclaim 14 in which the first amount and second amount are fixed.
 16. Themethod of claim 14 in which the first amount and second amount arevariable.
 17. The method of claim 14 in which the first amount isdifferent from the second amount.
 18. The method of claim 14 in whichthe first amount is equal to the second amount.
 19. The method of claim14 in which the first amount is less than the second amount.
 20. Themethod of claim 14 in which the first amount is greater than the secondamount.